Apply sysconf EXPLORERS restriction on startup

The sysconf EXPLORERS list restricting access to explore mode was being
evaluated and used when a player used the #exploremode command in-game,
or when specifying -X or OPTIONS=playmode:explore on the command line
when resuming a normal game, but not when starting an entirely new game.
When SYSCF is avilable, check for authorization early, similar to debug
mode authorization, to restrict access to explore mode to EXPLORERS
under (hopefully) all circumstances.

include/extern.h

@@ -2123,6 +2123,7 @@ extern int dohistory(void);
 extern void chdirx(char *, boolean);
 #endif /* CHDIR */
 extern boolean authorize_wizard_mode(void);
+extern boolean authorize_explore_mode(void);
 #endif
 #if defined(WIN32)
 extern int getlock(void);
@@ -3100,6 +3101,7 @@ extern void port_help(void);
 #endif
 extern void sethanguphandler(void(*)(int));
 extern boolean authorize_wizard_mode(void);
+extern boolean authorize_explore_mode(void);
 extern void append_slash(char *);
 extern boolean check_user_string(const char *);
 extern char *get_login_name(void);
@@ -3264,6 +3266,7 @@ extern void chdirx(const char *, boolean);
 #endif /* CHDIR */
 extern void sethanguphandler(void(*)(int));
 extern boolean authorize_wizard_mode(void);
+extern boolean authorize_explore_mode(void);
 
 /* ### vmsmisc.c ### */
 

src/cmd.c

@@ -965,10 +965,7 @@ enter_explore_mode(void)
     } else {
         const char *oldmode = !wizard ? "normal game" : "debug mode";
 
-#ifdef SYSCF
-#if defined(UNIX)
-        if (!sysopt.explorers || !sysopt.explorers[0]
-            || !check_user_string(sysopt.explorers)) {
+        if (!authorize_explore_mode()) {
             if (!wizard) {
                 You("cannot access explore mode.");
                 return ECMD_OK;
@@ -978,8 +975,6 @@ enter_explore_mode(void)
                 /* keep going */
             }
         }
-#endif
-#endif
         pline("Beware!  From explore mode there will be no return to %s,",
               oldmode);
         if (paranoid_query(ParanoidQuit,

src/options.c

@@ -10257,11 +10257,14 @@ set_playmode(void)
             gp.plnamelen = (int) strlen(strcpy(gp.plname, "wizard"));
         else
             wizard = FALSE; /* not allowed or not available */
-        /* force explore mode if we didn't make it into wizard mode */
+        /* try explore mode if we didn't make it into wizard mode */
         discover = !wizard;
         iflags.deferred_X = FALSE;
     }
-    /* don't need to do anything special for explore mode or normal play */
+    if (discover && !authorize_explore_mode()) {
+        discover = iflags.deferred_X = FALSE;
+    }
+    /* don't need to do anything special for normal play */
 }
 
 static void

src/restore.c

@@ -560,8 +560,8 @@ restgamestate(NHFILE *nhfp)
     if (newgameflags.debug) {
         /* authorized by startup code; wizard mode exists and is allowed */
         wizard = TRUE, discover = iflags.deferred_X = FALSE;
-    } else if (wizard) {
-        /* specified by save file; check authorization now */
+    } else if (wizard || discover) {
+        /* specified by save file; check authorization now. */
         set_playmode();
     }
     role_init(); /* Reset the initial role, race, gender, and alignment */

sys/libnh/libnhmain.c

@@ -50,7 +50,7 @@ extern void init_linux_cons(void);
 #endif
 
 static void wd_message(void);
-static boolean wiz_error_flag = FALSE;
+static boolean wiz_error_flag = FALSE, explore_error_flag = FALSE;
 static struct passwd *get_unix_pw(void);
 
 #ifdef __EMSCRIPTEN__
@@ -605,6 +605,22 @@ authorize_wizard_mode(void)
     return FALSE;
 }
 
+/* similar to above, validate explore mode access */
+boolean
+authorize_explore_mode(void)
+{
+#ifdef SYSCF
+    if (sysopt.explorers && sysopt.explorers[0]) {
+        if (check_user_string(sysopt.explorers))
+            return TRUE;
+    }
+    explore_error_flag = TRUE; /* not being allowed into explore mode */
+    return FALSE;
+#else
+    return TRUE; /* if sysconf disabled, no restrictions on explore mode */
+#endif
+}
+
 static void
 wd_message(void)
 {
@@ -614,9 +630,17 @@ wd_message(void)
             pline("Only user%s %s may access debug (wizard) mode.",
                   strchr(sysopt.wizards, ' ') ? "s" : "", tmp);
             free(tmp);
-        } else
+        } else {
+            You("cannot access debug (wizard) mode.");
+        }
+        wizard = 0; /* (paranoia) */
+        if (!explore_error_flag) {
             pline("Entering explore/discovery mode instead.");
-        wizard = 0, discover = 1; /* (paranoia) */
+            discover = 1;
+        }
+    } else if (explore_error_flag) {
+        You("cannot access explore mode."); /* same as enter_explore_mode */
+        discover = 0; /* (more paranoia) */
     } else if (discover)
         You("are in non-scoring explore/discovery mode.");
 }

sys/share/pcmain.c

@@ -720,6 +720,13 @@ authorize_wizard_mode(void)
     return FALSE;
 }
 
+/* similar to above, validate explore mode access */
+boolean
+authorize_explore_mode(void)
+{
+    return TRUE; /* no restrictions on explore mode */
+}
+
 #ifdef EXEPATH
 #ifdef __DJGPP__
 #define PATH_SEPARATOR '/'

sys/unix/unixmain.c

@@ -53,7 +53,7 @@ extern void init_linux_cons(void);
 #endif
 
 static void wd_message(void);
-static boolean wiz_error_flag = FALSE;
+static boolean wiz_error_flag = FALSE, explore_error_flag = FALSE;
 static struct passwd *get_unix_pw(void);
 
 int
@@ -964,6 +964,22 @@ authorize_wizard_mode(void)
     return FALSE;
 }
 
+/* similar to above, validate explore mode access */
+boolean
+authorize_explore_mode(void)
+{
+#ifdef SYSCF
+    if (sysopt.explorers && sysopt.explorers[0]) {
+        if (check_user_string(sysopt.explorers))
+            return TRUE;
+    }
+    explore_error_flag = TRUE; /* not being allowed into explore mode */
+    return FALSE;
+#else
+    return TRUE; /* if sysconf disabled, no restrictions on explore mode */
+#endif
+}
+
 static void
 wd_message(void)
 {
@@ -973,9 +989,17 @@ wd_message(void)
             pline("Only user%s %s may access debug (wizard) mode.",
                   strchr(sysopt.wizards, ' ') ? "s" : "", tmp);
             free(tmp);
-        } else
+        } else {
+            You("cannot access debug (wizard) mode.");
+        }
+        wizard = 0; /* (paranoia) */
+        if (!explore_error_flag) {
             pline("Entering explore/discovery mode instead.");
-        wizard = 0, discover = 1; /* (paranoia) */
+            discover = 1;
+        }
+    } else if (explore_error_flag) {
+        You("cannot access explore mode."); /* same as enter_explore_mode */
+        discover = 0; /* (more paranoia) */
     } else if (discover)
         You("are in non-scoring explore/discovery mode.");
 }

sys/vms/vmsmain.c

@@ -484,6 +484,13 @@ authorize_wizard_mode(void)
     return FALSE;
 }
 
+/* similar to above, validate explore mode access */
+boolean
+authorize_explore_mode(void)
+{
+    return TRUE; /* no restrictions on explore mode */
+}
+
 static void
 wd_message(void)
 {

sys/windows/windmain.c

@@ -1021,6 +1021,13 @@ authorize_wizard_mode(void)
     return FALSE;
 }
 
+/* similar to above, validate explore mode access */
+boolean
+authorize_explore_mode(void)
+{
+    return TRUE; /* no restrictions on explore mode */
+}
+
 #define PATH_SEPARATOR '\\'
 
 #if defined(WIN32) && !defined(WIN32CON)